Blowpipe apparatus



y 1948. E. MEINCKE EI'AL 2,444,900

BLOWPIPE APPARATUS Filed April 21, 1943 I5 Sheets-Sheet 1 59 v "25 U I i wwxswam 4/ HUGH T. SMITH ATTORNEY July 6, 1948. E. MEINCKE ETAL BLOWPIPE APPARATUS 3 Sheets-Sheet 2 Filed April 21, 1943 NTORS INVE EDWARD MEINCKE H T. SMITH HUG ATTORNEY July 6, 1948.

E. MEINCKE EIAL 2,444,900 BLQWPIPE APPARATUS Filed April 21, 1943 1/111. will/IA INVENTORS I" 10/ EDWARD MEINCKE HUGH SMITH ATTORNEY Patented July 6, 1948 Edward Meincke, Scotch Plains,

Smith, East Orange, N. 1.,

Linde Air Products Ohio and Hugh '1. aasignors to The Company, a corporation Application April 21, 1943, Serial No. 488,874

19 Claims.

This invention relates to blowpipe apparatus for thermochemically removing metal by a stream or jet of oxygen from metal bodies having a composition which resists the normal thermochemical action of a stream or jet of oxygen, such resistance being sufllcient to hinder or substan:

' tially prevent such normal removal of metal.

Examples of such metal bodies are ferrous metals, such as stainless steels, cast iron, and the like, and non-ferrous metals, such as copper, aluminum, nickel and various alloys. Such metal bodies are diiiicult or impossible to cut, deseam. desllrface or the like by the normal impingement of a stream of oxygen upon successive portions heated to their ignition temperature, or by heating flames which would provide sufilcient heat for the removal of metal from plain carbon steel by melting.

Previous attempts to thermochemically remove a surface layer of metal from a body of stainless steel, for instance, have met with little or no success. However, stainless steel plates have been cut or severed by placing a mild steel plate over the stainless steel plate, and cutting through the mild steel plate so that the molten slag from the mild steel kerf flows into the keri of the stainless steel. In such cutting operation, large amounts of mild steel are wasted, the cutting operation is relatively slow, and cuts of poor quality are produced.

The present invention is particularly applicable to the thermochemical cutting, deseaming or desurfacing of metals and alloys which have heretofore resisted such thermochemical operations. Metal is thermochemically removed from a metal body, heretofore resisting such action, by introducing a finely-divided oxidizable adiuvant material such as iron powder into the zone of action of the oxygen stream or let in order to produce reaction products sufllciently fluid that successive portions of the metal body may be thermochemically removed when a relative movement is efl'ected between the body and the oxygen stream or jet. Preferably, the powdered adiuvant materlal is carried directly into the reaction zone by the stream or jet of metal-removing oxygen.

It is an object of the present invention to provide an improved apparatus for introducing the adjuvant material into the stream of metal-removing oxygen, which stream of oxygencarrles the adiuvant material into the reaction zone. Among other objects of this invention are to provide apparatus for introducing finely-divided adiuvant material into a stream of metal-removin; oxygen in-such manner that the material will be substantially uniformly distributed in the stream of oxygen, and the metal-removing eifectiveness of the oxygen stream or let will be rendered uniform across the width thereof; to provide such apparatus wherein'the finely-divided material is introduced into the oxygen stream in the oxygen blowpipe passage of a blowpipe nozzle; to provide such apparatus whereby the material is introduced at the most eilectivc point in the oxygen discharge passage; to provide such a paratus which follows, as far as is practicable, the design of cutting and d nozzles and blowpipes in current usage; and to provide other features which will be apparent as the following description proceeds.

In accordance with this invention, oxygen is introduced into the oxygen discharge passage of a blowpipenozzle through a tube extending into the passage from therear toward the trout thereof in spaced relation to the wall thereof. and terminating at a point spaced from the forward end thereof. Finely-divided adjuvant material is supplied to the space surrounding the tube by a plurality of small ports or ducts extending through the wall of the nozzle from an annular chamber surrounding the nozzle. The ducts are positioned in the nozzle wall in such a manner that they pass between but do not communicate with the usual longitudinal-preheat passages in the nozzle wall. As the oxygen stream passes out of the tube and into the discharge passage 0! the nozzle,' it expands, creating an aspiration eflect which draws the adiuvant material into the oxygen stream from the space around the tube. A plurality of small orifices advantageously are provided in the space surrounding the oxygen discharge tube for distributing powder uniformly around the periphery of the oxygen stream and for arresting powder back flashes. The mixture of oxygen and finely-divided adjuvant material, opon passing out of the discharge passage of the nozzle, may be brought into contact with a heated portion of a metal body to eflect thermochemical removal of metal therefrom.

Apparatus constructed in accordance with this invention is illustrated in the ac ompanying drawings, in which: 1

Fig. l is a longitudinal sectional View of the head end of a blowpipe constructed in accordance with this invention. taken along the line l-i in Fig. 2

Fig. 2 is a cross-sectional view taken along the line 2-2 of Fig. 6;

Fig. 8 is a cross-sectional view taken along the line 3-3 1'18. 1;

Fig. 4 is a longitudinal sectional view oi a part of a modified form of blowplpe:

Fig. 5 is a cross-sectional view taken along the line H oi Fig. 4;

Fig. 6 is a side elevational view, partly broken away and in section, of the apparatus of the invention;

Fig. 7 is a longitudinal sectional view of a modified form of blowplpe nozzle;

Fig. 8 is a bottom end view of the nomie of Fig. '7;

Fig. 9 is a longitudinal sectional view of the front end of a modified form of blowplpe;

Fig. 10 is a cross-sectional view taken along the line Iii-l3 of Fig. 9;

Fig. 11 is a perspective view of a part of the blowplpe of Fig. 9;

Fig. 12 is a side elevational view, partly broken away and in section, of a modified form of blowipe nozzle;

Fig. 13 is a cross-sectional view taken along the line |3- i3 of Fig. 12; and

Fig. 14 is an end view of the nozzle as seen from the left in Fig. 12.

In the embodiment of this invention illustrated in Figs. 1, 2, and 3, a blowplpe nozzle unit including a tubular barrel or nozzle ll having a wall and front and rear ends is detachably secured in a head 13 by an annular nut ii, in a well-known manner. The nozzle II is provided with a plurality of annulariy arranged longitudinal preheat passages I! in its wall for a combustible preheating medium having inlets arranged in a ring or circumferential row near the rear end of the nozzle, and with a central longitudinal bore or oxygen passage 19 around which the preheat pas: sages ll are arranged. Near the rear end of the nozzle a plurality of circumferentially spaced ports 23 for powder are drilled transversely through the wall of the nozzle from the outside thereof to the oxygen passage I! with their axes lying in planes between combustible gas passages H. The ports 23 are located between the preheat passages H in non-communicative relation therewith, as shown clearly in Fig. 3, have entrances arranged in a ring or circumferential row on the outside of the nozzle spaced forwardly from the ring or row of preheat passage inlets, and are inclined or converge forwardly and inwardly toward the axis oil! the nozzle. An oxygen gas discharge tube or injector tube 25, which has an annular flange adjacent to its rear end fitting snugly in the rear end of the passage is, is carried by the nozzle II and extends forwardly in spaced relation to the wall of the passage IB. Tube 25 terminates at a point well ahead of the ducts 23 and. spaced from the forward or outlet end of the passage IS. The front portion of the tube 25 carries a plurality of laterally extending circumferentially spaced fins 21 fitting snugly in the passage l3 and dividing the discharge end of the annular space around the tube 25 into a plurality of small ducts.

A combustible preheating medium, such as an oxyacetylene gas mixture, may be distributed to the passages I! by an annular distributing chamber 3i supplied by a communicating supply duct comprising a conduit 33 secured in a connecting bore 38 in the head i3.

Finely-divided adjuvant material may be supplied to the ports 23, and thence to the annular space 23, by a tube 31 secured in a connecting bore 39 leading into an annular powder distribut- 4 ing chamber or header 4| surrounding a rear portion of the nozzle barrel H and communicatlnl with the entrances of all the ports. As shown in Figs. 2 and 3, the bore 33 opens into the annular chamber ll above the longitudinal axis thereof. However. a good distribution of powder in the distributing chamber is also obtainable if the bore opens into the chamber at a locality to one side of the axis, as does the bore 33 shown in Figs. 4 and 5. A suitable source of powder, as shown in Fig. 6, may comprise a closed hopper 30 connected to the tube "by a flexible hose 2, and having an inlet pipe 44 through which gas under pressure may enter above the powder level.

Oxygen enters the discharge tube 23 through a communicating supply duct comprising a conduit 43 secured in a bore 45 in head i3, and is then discharged into the relatively large passage l9, aspirating into the passage a plurality of small streams of powder flowing smoothly in substantially a straight line from the annular space 29. The powder and oxygen mix intimately together while passing along the passage i9, and may be discharged against a body of metal preheated by the flames from the passages ii, thereby removing metal from the body thermochemically.

Adequate gas-tight seals preventing leakage between the oxygen, fuel gas, and powder passage and ducts are provided by two annular conical seats 46 and 48 near the rear end of the nozzle H, which seat tightly on corresponding seating surfaces in the body l3. Seating surface 46 is arranged between the ring of preheat passage inlets and the ring of powder port ontrances.

It is desirable that powder from the passage 33 be controlled so as to enter the nozzle ii only when metal-removing oxygen is flowing through the tube 25. This is accomplished by placing a suitable shut-off valve 41 in the bore 39 of the head i3. The valve 41 illustrated, by way of example only, is an ordinary rotatable plug valve secured in a cross bore 49 of the head 13 and having a through passage 5| which may be rotated into and out of register with the bore 39. The valve 41 includes a stem 53 projecting from the side of the body I 3 and engaging a crank 55 to which an operating rod or wire 51 is attached by a set screw. With this arrangement, the operator of the blowplpe can start or stop the flow of powder to the nozzle H by manipulating the wire 51.

In Fig. 6 there is shown an arrangement whereby the operator may control in unison the flows of powder and metal-removing oxygen to the nozzle ii, The blowplpe handle 59 has the usual long lever 3|, fulcrumed between its ends, and engaging at its rear end the stem 83 of a spring-closed valve controlling the flow of metalremoving oxygen to the nozzle II. The lever ii is connected through a suitable linkage 65 to the connecting rod 51, the construction and arrangement being such that when the operator actuates the lever ii to start or stop the flow of oxygen, the powder control valve 41 is rotated to start or stop the flow of powder. The linkage may be such that the flows of oxygen and powder start and stop simultaneously, or any other predetermined relation may be maintained, such that the flow of powder may be started and stopped either before or after the oxygen.

The particular linkage 65 shown in Fig. 6, by

way oi illustration only, comprises a rotatable element 31 pivoted at 33 to a stationary support II withinthe handle 63. An L-shaped connecting link I3 is pivotally secured at one end to the element 31 on one side 01' the pivot 63. and at its other end to the valve-operating lever 3i, whereby movement of the lever 3| cases the element 31 to tum through part cl a revolution. A turnbuckle IB is pivotally secured at one end to the element 31 on the opposite side of the pivot 33, and at its other end grips the connecting rod or wire ll, whereby rotation of the element 31 opens or closes the valve 41. A return spring I1 is secured at one end to the handle it, and at its other end engages the pivoted element 31, for assisting the return of the lever II to its raised position when released by the operator, thereby closing the oxygen control valve 63 and the powder control valve 31. r

Figs. 7 and 8 show a modified form of nozzle which is designed to provide a preheating flame of the externally-mixed type. wherein the combustible fluid and the oxygen are not mixed together until after discharge from the nozzle. The nozzle I! is generally similar to that shown in Fig. l, and may be mounted in an identical head. However, it diiIers from the nozzle of Fig. 1 mainly by the provision of an inturned annular deflector lip or flange OI on the front of the nozzle, extending across the outlets of the preheat passages," in slightly spaced relation thereto; and by the provision of a greater number of powder inlet ports 34. In the operation of this nozzle, a constant flow of oxygen at a relatively low rate (without powder) is maintained from the outlet of the passage 35, and combustible fluid such as acetylene gas from the separate adjacent outlets of passages lip 3| into the central stream of oxygen leaving the nozzle. The two gases thus mix together intimately only outside the nozzle and, on ignition, burn with a hot flame which will not flash back within the nozzle.

when the flame has brought the metal body to the proper temperature, the rate of flow of oxygen through the passage 35 is increased by the operator, and the flow of adjuvant powder into the oxygen is begun. The preheating flame react with a metal body from.

In another embodiment of the invention, shown in Figs. 9, 10, and 11, a nozzle 87, quite similar in many respects to that of Fig. l, is secured to a blowplpe head 89 by a hollow nut 9i. Oxygen is supplied to a discharge tube 93, carried in the passage 95 of the nozzle, by a conduit 91 secured in a connecting bore 99 in the head 89. A combustible preheating fluid, such as an oxy-acety- III fitting snugly over and welded to the outside of the nozzle 31 in spaced relation to head It. Collar IIB has an inwardly open channel closed 83 is deflected by the annular sponding parts of Fig.

- chamber I3I of Q by the outside surface of the nonle. divided adiuvant material is supplied to the chamber II3'by a conduit III conected to a'suitable source oi supply, such as a powder hopper oi the type shown in Fig. 6, and thence passes through the connecting ports I" to the annular space III around tube 33.

Fig. 11 shows in detail the oxygen discharge tube 33, which is similar to the discharge tubes 01' Figs. 1 and 12.

In another embodiment of the invention, shown in Figs. 12, 13, and 14, the nozzle I2I and oxygen discharge tube I23 are identical with the corre- 9. However, the powder is fed .into the nozzle by a device which may be actuated to start or stop the powder feed at will.

construction oi the if desired. Two' narrow guide collars I25 and I 21 are secured on the nozzle I2 I, on opposite sides of powder inlet ports I36 in spaced relation to one another, in any suitable manner, as by clamping tributing header ring I2! is mounted on the nozzle I2I for rotational sliding movement thereon. The ring I23 has an annular powder distributing generally triangular cross section, and a plurality of short ducts I33 leading from the chamber corresponding to and arranged to register with the outer ends of the powder inlet ports I of the nozzle. suitable packing material are disposed in mating grooves between the ring I29 and the collars I25 and I21. Powder is supplied to the annular chamber I3I by a conduit HI welded to the ring I29 and connected to a suitable source of supply (not shown).

Whlen operating a blowpipe embodying the structure of Fig. 12, the operator so adjusts the ring I23 that the ducts I33 register with the ports I35, as shown in Fig. 13, thereby permitting powdered adiuvant material to flow into the nozzle. When the operator wishes to stop the powder flow, he simply turns the ring I29 an amount sufllclent to take the ducts I33 and ports I35 out of registry with one another, as shown in Fig. 14.

from the ring I29,

Adjustment is facilitated by a pin I43 projecting which may abut against a movement-limiting stop pin I45 when the ring is adjusted for powder flow, and may abut against a second movement-limiting stop pin I41, when the ring is adjusted to stop the powder flow.

Although several different embodiments of this invention have been described, it will be understood that various changes in the apparatus can be made and that the principles of this invention are applicable to the removal of metal from metal bodies other than those described and to the use of adjuvant materials other than iron powder. In addition, other changes may be made without departing from the spirit and scope of the invention as defined in the appended claims.

This invention constitutes an improvement on the apparatus disclosed and claimed in application Serial No. 584,715, which was filed March 24, 1945, as a continuation-in-part of abandoned application Serial No. 456,667, filed August 29, 1942, both of which applications are assigned to The Linde Air Products Company.

What is claimed is:

1. A blowpipe having a head; a nozzle carried by said head, said nozzle having a longitudinal oxygen passage therethrough and a plurality of longitudinal preheating gas passages arranged around said oxygen passage; a gasdischarge tube extending intosaid oxygen passage from the rear toward the front thereof in spaced relation to the Finely- Rings I31 and I38 of said nozzle being wall thereof, and terminating at a point spaced from the forward end said oxygen passage; said head having oxygen and preheating gas supply ducts in communication respectively with said tube and said reheating gas passa es; an annular powder distributing header surrounding said nozzle in spaced relation to said head; and said nozzle being provided with a plurality of ports transversely of said nozzle between said preheating gas passages in non-communicative relation therewith and connecting said header with the space surounding said gas discharge tube.

2. A blowpipe according to claim 1, wherein said header comprises a collar fitting snugly over said nozzle, said collar having an inwardly open channel closed by the outside surface of said nozzle.

3. A blowpipe nozzle having a longitudinal oxygen passage therethrough and a plurality of iongitudinal preheating gas passages arranged around said oxygen passage; said nozzle being provided with a plurality of ports passing transversely between the inside and the outside thereof between said preheating gas passages in noncommunicative relation therewith; and a header slidably mounted on said nozzle, said header having a distributing chamber therein, and said header having a plurality of ducts corresponding to said ports leading from said chamber, said header being slidable on said nozzle to bring said ducts into and out of register with said ports at,

will.

4. A blowpipe, said nozzle having a longitudinal oxygen passage therethrough and a plurality of longitudinal preheating gas passages surrounding said oxygen passage; said nozzle being provided with a plurality of ports passing transversely between the inside and the outside thereof between said preheating gas passages in non-communicative relation therewith; a pair of guide collars secured over said nozzle on opposite sides of said ports; a powder distributing header mounted on said nozzle, between said guide collars, for rotational sliding movement thereon, said header having an annular chamber therein and a plurality of ducts leading from said chamber, the construction and arrangement being such that said ducts may be brought into and out of register with said ports by turning said header; and a pair of stops cooperating with said header limiting the movement thereof, the arrangement being such that when said header abuts against one of said stops, said ducts and said ports are out of register, and when said header abuts against the other of said stops, said ducts and said ports are in register.

5. A blowpipe nozzle provided with an oxygen passage, and a plurality of fuel gas passages adjacent to said oxygen passage, all of said passages having outlets adjacent to one another in the forward end of said nozzle; an oxygen discharge tube extending into said oxygen passage in spaced relation to the wall thereof and terminating at a point spaced from the forward end of said nozzle; provided with passage means for supplying powder to the space surrounding said tube; and deflector means on said nozzle extending across the outlets of said fuel gas passages in spaced relation to the forward end of said nozzle for deflecting fuel gas toward the stream of oxygen leaving said oxygen passage, whereby said fuel gas and at least a part of. said oxygen mix together intimately only outside of the nozzle to form a combustible gas mixture.

6. A blowipe nozzle according to claim wherein said passage means for supplying powder includes a plurality of ports provided in said nozzle extending transversely between the inside and the outside thereof, said ports being located between but in non-communicative relation with said fuel gas passages; in combination with a header for distributing powder to all of said ports.

7. A blowpipe device comprising a nozzle having a central longitudinal passage therethrough; said nozzle being provided with a plurality of iongltudinal passages around said central passage; an annular powder distributing header secured to said nozzle and having a chamber therein; and said nozzle being provided with a plurality of ports passing transversely of said nozzle between the inside and the outside thereof, said ports passing between said second-named passages in non-communica'tive relation therewith, and said ports establishing communication between said chamber and said central passage.

8. A blowpipe device comprising a nozzle having a central longitudinal passage therethrough; said nozzle being provided with a plurality of iongitudinal passages around said central passage, and a plurality of ports passing transversely of said nozzle between the inside and the outside thereof and passing between said second-named passages in non-communicative relation therewith; a pair of guide collars mounted over said nozzle on opposite sides of said ports; and a powder distributing header mounted on said nozzle, between said guide collars, for rotational sliding movement thereon, said header having an annular chamber therein and a plurality of ducts leading from said chamber, the construction and arrangement being such that said ducts may be brought into and out of register withsaid ports by turning said header.

9. A blowpipe nozzle having a first longitudinal passage therethrough; said nozzle being provided ill) with a plurality of longitudinal passages arranged around said first passage; all of said passages having outlets adjacent to but separate from one another; said nozzles having a plurality of ports extending transversely of said nozzle between said first-mentioned passage and the outside of the nozzle, said ports passing between said secondnamed passages in non-communicative relation therewith; and deflector means on said nozzle extending across the outlets of said second-named passages in spaced relation to the forward end of said nozzle for deflecting gas toward the stream of gas leaving said first passage to mix therewith only outside of said nozzle.

10. A blowpipe comprising a nozzle having a first longitudinal passage for metalremoving oxygen and a plurality of longitudinal preheating gas passages arranged around said first passage; an oxygen injector tube extending forwardly into said first passage in spaced relation to the wall thereof but terminating at a position within said first passage spaced from the discharge end thereof; and means providing a powder distributing chamber outside of and extending around said nomle; saidnozzle having a plurality of ports extending transversely between said preheating gas passages in non-communicative relation therewith and connecting said powder distributing chamber with the space in said first passage around said oxygen injector tube.

11. A blowpipe comprising a nozzle having a first longitudinal passage for metal-removing oxygen and a plurality of longitudinal preheating gas passages arranged around said first passage; an oxygen injector tube extending forwardly into said first passage in spaced relatior to the wall thereof but terminating at a positior within said first passage spaced from the discharge end thereof; and means providing a. powder distributing chamber outside of and extending around said nozzle; said nozzle having a plurality of ports extending transversely between said preheating gas passages in non-communicative relation therewith and connecting said powder distributing chamber. with the space in said first passage around said oxygen injector tube, said ports being inclined inwardly and forwardly.

12. A blowpipe comprising a nozzle having a first longitudinal passage for metal-removing oxygen and a plurality of longitudinal preheating gas passages arranged around said first passage; an oxygen injector tube extending forwardly into said first passage in annularly spaced relation to the wall thereof but terminating at a position within said first passage spaced from the discharge end thereof; means providing a powder distributing chamber outside of and extending around said nozzle; said nozzle having a plurality of powder ports extending. transversely between said preheating gas passages in non-communicative relation therewith and connecting said powder distributing chamber with the space in said first passage around said oxygen discharge tube; and a plurality of laterally extending circumferentially spaced fins on the outside of said tube adjacent the forward end thereof dividing a part of the annular space around said tube into a plurality of small ducts near the front of said tube for conducting a plurality of streams of powder from said annular space into said first passage ahead of said tube.

13. A blowpipe comprising a nozzle having a first longitudinal passage for metal-removing oxygen and a plurality of longitudinal preheating gas passages around said first passage; an oxygen injector tube carried by said nozzle as a unit therewith within said first passage, said tube having a rear portion engaging the wall of said first passage and a, front portion spaced from said wall and terminating within said first passage at a position spaced from the discharge end thereof; and means providing a powder distributing chamber outside of and extending around said nozzle; said nozzle having a plurality of ports extending transversely between said preheating gas passages in non-communicative relation therewith and connecting said powder distributing chamber with the space in said first passage around said oxygen injector tube.

14. A blowpipe comprising a head; a nozzle detachably carried by said head, said nozzle having a first longitudinal passage for metal-removing oxygen and a plurality of longitudinal preheating gas passages arranged around said first passage; an oxygen injector tube extending forwardly into said first passage in spaced relation to the wall thereof but terminating at a position within said first passage spaced from the discharge end thereof; said nozzle having a. plurality of ports extending transversely between said preheating gas passages in non-communicative relation therewith from the space around said in- Iector tube to the outside of said nozzle; said head having an oxygen duct for supplying oxygen to ;aid injector tube, a preheating gas duct for sup- :lying preheating gas to said preheating gas pas- :ages, and a powder distributing chamber exending around said nozzle for supplying powder said powder ports; and means providing seals netween said nozzle and said head in positions for reventing leakage between said oxygen duct, said vreheating gas duct, and said chamber.

15. A blowpipe nozzle comprising a tubular barrel having a wall and front and rear ends, said barrel being provided with a longitudinal oxygen passage, said wall being provided with a plurality of longitudinal combustible gas passages arranged around said oxygen passage, said combustible gas passages having inlets arranged in, a ring near said rear end, and said barrel being provided with a plurality of powder ports extending transversely through said wall between said combustible gas passages in non-communicative relation there"- with from said oxygen passage to the outside of said barrel, said ports having entrances arranged in a ring on the outside of said barrel spaced forwardly from said first-named ring;' and an annular seating surface between said rings adapted to abut against a corresponding annular seat in a blowpipe to provide a tight seal rings.

16. A :blowpipe nozzle comprising a. tubular barrel having a wall and front and rear ends, said barrel being provided with a longitudinal oxygen passage, said wall being provided with a plurality of longitudinal combustible gas passages arranged around said oxygen passage, said combustible gas passages having inlets arranged in a ring near said rear end, and said wall being provided with a plurality of powder ports extending transversely through said wall between said combustible gas passages in non-communicative relation therewith from said oxygen passage to the outside of said barrel, said ports being inclined inwardly toward the front end of said oxygen passage, said ports having entrances arranged in a ring on the outside of said barrel spaced forwardly from said first-named ring; and an annular seating surface between said rings adapted to abut against a corresponding annular seat in a blowpipe to provide a tight seal between said rings.

17. A blowpipe nozzle unit comprising a. tubular barrel having a wall and front and rear ends, said barrel being provided with a longitudinal oxygen passage, said wall being provided with a plurality of longitudinal combustible gas passages arranged around said oxygen passage, said combustible gas passages having inlets arranged in a ring near said rear end, and said wall being provided'with a plurality of circumferentially spaced powder ports extending transversely-through said wall between said combustible gas passages in non-communicative relation therewith from said oxygen passage to the outside of said barrel, said ports having entrances arranged in a ring on the outside of said barrel spaced forwardly from said first-named ring; and an annular seating surface between said rings adapted to abut against a corresponding seat in a blowpipe to provide a tight seal between said rings; said nozzle also comprising an oxygen injector tube within said oxygen passage having a rear portion engaging said wallbehind said powder ports, said tube extending forwardly in spaced relation to said wall and terminating at a position between said ports and said front end of said barrel.

18. A metal-removing blowpipe apparatus comprising, in combination, a blowpipe nozzle having a central longitudinal bore extending therethrough, a plurality of combustible gas passages extending longitudinally of and spaced apart around said bore, and adjuvant powder passage means constructed and arranged to deliver adjuvant powder into an oxygen stream passed through said bore, such powder passage means including a plurality of powder'passages formed in said nozzle and spaced apart around said bore between said' v and conversing forwardly toward the axis oi said bore but in non-communicative relation with said combustible sas passalesil means secured to said meals and providing a powder distributing chamber extendint around said nozzle and communieating with the entrances of said converging powder passaaes but not communicating with said combustible as passages; and a plurality 01' condnits ior separately supplying oxygen to said bore, combustible (as to said combustible gas passages and adinvant powder to said powder distributing chamber.

19. A metal-removing biowpipe apparatus in accordance with claim 18, wherein said plurality of powder passases pass transversely between said combustible as passases in non-communicative relation tlierewith.

EDWARD MEINCKE. HUGH '1. SMITH.

assurances 0mm The foilowina references are of record in the tile oi this patent:

mp0s DQ100089 Feb. 18, 1873 Number Number 25 192,000 198,627 494,888

Name Date Root Aug. 8, 1888 Delhaye Nov. 2, 1886 Phillips June 4, 1901 Davis Fe 25, 1902 Bowland Mar. 2, 1909 Harrison Aug. 23, 1910 Dunn Jan. 2, 1912 Leonard et a1. June 3, 1919 Cartwright May 25, 1920 Jenkins Apr. 11, 1922 Smith Jan. 8, 1924 Horn June 9, 1925 Wulfi Nov. 9, 1926 stedwell May 14, 1929 Donaldson et al Sept. 9, 1930 McLaughlin May 3, 1932 Jenkins Nov. 22, 1932 Vawter May 9, 1933 Ness Nov. 21, 1939 Bhelburne Dec. 31, 1940 FOREIGN PATENTS Country Date Germany Nov. 29, 1907 Great Britain May 28, 1923 Germany Mar. 29, 1930 

